Publications by authors named "Liang Ren Zhang"

Background: The toxicity of excessive glutamate release has been implicated in various acute and chronic neurodegenerative conditions. Vesicular glutamate transporters (VGLUTs) are the major mediators for the uptake of glutamate into synaptic vesicles. However, the dynamics and mechanism of this process in glutamatergic neurons are still largely unknown.

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Molecular fingerprints are the workhorse in ligand-based drug discovery. In recent years, an increasing number of research papers reported fascinating results on using deep neural networks to learn 2D molecular representations as fingerprints. It is anticipated that the integration of deep learning would also contribute to the prosperity of 3D fingerprints.

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A highly efficient di--glycosyltransferase GgCGT was discovered from the medicinal plant . GgCGT catalyzes a two-step di--glycosylation of flopropione-containing substrates with conversion rates of >98%. To elucidate the catalytic mechanisms of GgCGT, we solved its crystal structures in complex with UDP-Glc, UDP-Gal, UDP/phloretin, and UDP/nothofagin, respectively.

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Constitutive activation of signal transducer and activator of transcription 3 (STAT3) plays important roles in oncogenic occurrence and transformation by regulating the expression of diverse downstream target genes important for tumor growth, metastasis, angiogenesis and immune evasion. Feasibility of targeting the DNA-binding domain (DBD) of STAT3 has been proven previously. With the aid of 3D shape- and electrostatic-based drug design, we identified a new STAT3 inhibitor, LC28, and its five analogs, based on the pharmacophore of a known STAT3 DBD inhibitor.

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Combined use of drugs is a hot spot in the research of new drugs nowadays, and traditional Chinese medicine (TCM) is a classic practice in the combined use of drugs. In this paper, the compatibility of TCM prescriptions and the related properties of composed herbs were calculated and studied to verify and discuss the feasibility of the results in guiding compatibility. Research Group on New Drug Design, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences had established a structured database of TCM prescriptions by using traditional Chinese medicine inheritance support system (TCMISS V2.

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Albumin-based nanoparticles (NPs) are a promising technology for developing drug-carrier systems, with improved deposition and retention profiles in lungs. Improved understanding of these drug-carrier interactions could lead to better drug-delivery systems. The present study combines computational and experimental methods to gain insights into the mechanism of binding of albuterol sulfate (AS) to bovine serum albumin (BSA) on the molecular level.

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Alpha7 nicotinic acetylcholine receptor(α7 nAChR) is a ligand-gated ion channel critical for cognition, learning and memory. Deficiency of neuronal α7 nAChR has been implicated in the cognitive deficits and neuropsychiatric disorders. Chemical activation of α7 nAChR improves neurological functions in animal models.

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CD38 is a multifunctional enzyme expressed in a variety of mammalian tissues, its catalytic activity was involved in a wide range of physiological processes. Based on the reported inhibitor of human CD38 NADase, 33 purine derivatives were designed and synthesized. The biological activity assay showed that compounds 20 and 38 exhibited almost the same extent of inhibitory activities on human CD38 NADase as the lead compound H2.

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CD38 is a multifunctional membrane enzyme and the main mammalian ADP-ribosyl cyclase, which catalyzes the synthesis and hydrolysis of cADPR, a potent endogenous Ca(2+) mobilizing messenger. Here, we explored the role of CD38 in the neural differentiation of mouse embryonic stem cells (ESCs). We found that the expression of CD38 was decreased during the differentiation of mouse ESCs initiated by adherent monoculture.

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Aim: Alpha7-nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca(2+)-permeable ion channel implicated in cognition and neuropsychiatric disorders. Activation of α7 nAChR improves learning, memory, and sensory gating in animal models. To identify novel α7 nAChR agonists, we synthesized a series of small molecules and characterized a representative compound, Br-IQ17B, N-[(3R)-1-azabicyclo[2,2,2]oct-3-yl]-5-bromoindolizine-2-carboxamide, which specifically activates α7 nAChR.

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Licorice has been shown to affect the activities of several cytochrome P450 enzymes. This study aims to identify the key constituents in licorice which may affect these activities. Bioactivity assay was combined with metabolic profiling to identify these compounds in several complex licorice extracts.

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Airway hyperresponsiveness (AHR) and airway inflammation are key pathophysiological features of many respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). To evaluate the treatment responses of procaterol and CD38 inhibitors in an ozone-induced AHR mice model, we hypothesized that procaterol and two synthetic CD38 inhibitors (Compounds T and H) might have therapeutic effects on the ozone-induced AHR mice model, and the nuclear factor-kappaB (NF-κB) pathway and the CD38 enzymatic activity might be involved in the mechanisms. With the exception of the Control group, ozone exposure was used to establish an AHR model.

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In this study, a series of bioreducible poly(amidoamine)s grafting different percentages of cholesterol (rPAA-Ch14: 14%, rPAA-Ch29: 29%, rPAA-Ch57: 57% and rPAA-Ch87: 87%) was synthesized and used for siRNA delivery. These amphiphilic polymers were able to self-assemble into cationic nanoparticles in aqueous solution at low concentrations. The nanoparticle formation was evidenced via cryo-transmission electron microscope (Cryo-TEM) and dynamic light scattering analysis.

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Antisense oligonucleotides and siRNAs are potential therapeutic agents and their chemical modifications play an important role to improve the properties and activities of oligonucleotides. Isonucleoside is a type of nucleoside analogue, in which the nucleobase is moved from C-1 to other positions of ribose. In this report, a novel isonucleoside 5 containing a 5'-CH(2)-extended chain at the sugar moiety was synthesized, thus isoadenosine 5a and isothymidine 5b were incorporated into a DNA single strand and siRNA.

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Ubiquitin-proteasome pathway (UPP) is one of the ways utilized for selective degradation of many proteins in cells, and the 20S proteasome takes the functional machinery where hydrolysis of targeted proteins takes place. Based on existing peptide inhibitors, a series of novel tripeptidic tetrazoles have been designed, synthesized, and the structures have been confirmed with 1H NMR, MS and elemental analysis. Among them, three compounds (6b, 6d and 6h) showed inhibitory activities of ChT-L of 20S proteasome.

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Gemcitabine (GEM) is a nucleoside analog agent against a wide variety of tumors. To overcome its limitation of rapid metabolism in vivo that results in short circulation time and poor antitumor efficacy, a novel prodrug (CLA-GEM conjugate) has been developed through the covalent coupling of conjugated linoleic acid (CLA) to N(4)-amino group of GEM. The chemical structure of CLA-GEM conjugate was identified by NMR, FTIR and other methods.

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Due to the absence of safe and effective carriers for in vivo delivery, the applications of small interference RNA (siRNA) in clinic for therapeutic purposes have been limited. In this study, a biodegradable amphiphilic tri-block copolymer (mPEG(2000)-PLA(3000)-b-R(15)) composed of monomethoxy poly(ethylene glycol), poly(d,l-lactide) and polyarginine was synthesized and further self-assembled to cationic polymeric nanomicelles for in vivo siRNA delivery, with an average diameter of 54.30 ± 3.

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Antisense oligonucleotides (ASONs) and siRNAs have been applied extensively for the regulation of cellular and viral gene expression, and RNAi is currently one of the most promising new approaches for anti-tumor and anti-viral therapy. In order to improve bioactivity properties and physicochemical properties of siRNA, we synthesized a novel class of ASONs incorporated with amino-isonucleoside ( and ) for investigation on basic physicochemical properties. Then we designed amino-isonucleoside ( , and ) incorporated siRNA .

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Human CD38 is a novel multi-functional protein that acts not only as an antigen for B-lymphocyte activation, but also as an enzyme catalyzing the synthesis of a Ca(2+) messenger molecule, cyclic ADP-ribose, from NAD(+). It is well established that this novel Ca(2+) signaling enzyme is responsible for regulating a wide range of physiological functions. Based on the crystal structure of the CD38/NAD(+) complex, we synthesized a series of simplified N-substituted nicotinamide derivatives (Compound 1-14).

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A convenient trifluoromethylation method was firstly applied to the synthesis of 8- CF(3)-purine nucleosides. On the basis of this method, new protection and deprotection strategies were developed for the successful synthesis of the trifluoromethylated cyclic-ADP-ribose mimic, 8-CF(3)-cIDPRE 1. Using intact, fura-2-loaded Jurkat T cells compound 1 and 2',3'-O-isopropylidene 8-CF(3)-cIDPRE 14 were characterized as membrane-permeant cADPR agonists.

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Purpose: The restriction of drug transporting across the blood-brain barrier (BBB) and the limit of drug penetrating into the tumor tissue remain the major obstacles for brain tumor chemotherapy. In the present study, we developed a functionalized liposomal nanoconstruct, epirubicin liposomes modified with tamoxifen (TAM) and transferrin (TF), for transporting drug across the BBB and afterwards targeting the brain glioma.

Methods: Evaluations were performed on the murine C6 glioma cells, the C6 glioma spheroids, the BBB model in vitro and the brain glioma-bearing rats.

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Chemotherapy for brain glioma has been of limited value due to the inability of transport of drug across the blood-brain barrier (BBB) and poor penetration of drug into the tumor. For overcoming these hurdles, the dual-targeting daunorubicin liposomes were developed by conjugating with p-aminophenyl-alpha-D-manno-pyranoside (MAN) and transferrin (TF) for transporting drug across the BBB and then targeting brain glioma. The dual-targeting effects were evaluated on the BBB model in vitro, C6 glioma cells in vitro, avascular C6 glioma tumor spheroids in vitro, and C6 glioma-bearing rats in vivo, respectively.

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Intracellular Ca(2+) mobilization plays an important role in a wide variety of cellular processes, and multiple second messengers are responsible for mediating intracellular Ca(2+) changes. Here we explored the role of one endogenous Ca(2+)-mobilizing nucleotide, cyclic adenosine diphosphoribose (cADPR), in the proliferation and differentiation of neurosecretory PC12 cells. We found that cADPR induced Ca(2+) release in PC12 cells and that CD38 is the main ADP-ribosyl cyclase responsible for the acetylcholine (ACh)-induced cADPR production in PC12 cells.

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Highly potent N-substituted delta-lactams have been rationally designed and synthesized by a concise route with a one-pot tandem reaction as key step. These iminosugars show weak inhibition of wild-type beta-glucocerebrosidase but 3- to 6-fold increases in mutant enzyme activity (N370S).

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Four types of beta-carboline-nucleoside conjugates were synthesized. The binding affinities of these beta-carboline-nucleoside conjugates , and to TAR RNA were evaluated by affinity capillary electrophoresis. The data of binding affinities to TAR RNA show that conjugates and are stronger binders than the parent compound .

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